The Optima Automated edition was designed to be completely automated. This Reverse Osmosis Filter system Designed specifically for the needs of Aquarium Saltwater Reef Hobbyists in mind, this system includes all the components needed to create an auto top off system for your aquarium. In the creation of a good auto top off system you will need many different fittings and accessories that are often forgotten until the last minute. With this system we have thoughtfully added all of the fittings and tubing needed to create a well designed auto top off setup and the customer support availabilty you may need along the way. This system includes an auto shut off device that senses the back pressure caused by the float valve(included) when it reaches your desired fill level. The reason this is so important is because an RO system will continuously waste water until it is manualy shut down. This system avoids the manual shut down as it senses that the need for water has ended and turns itself off. This system is completely non electric! It functions using pressure.